(a) Field of the Invention
The present invention relates to a thin film transistor array substrate and its manufacturing method.
(b) Description of the Related Art
In general, display devices, such as a liquid crystal display (LCD) or an organic light-emitting device, that display images include substrates on which a plurality of pixel areas are defined. The pixel areas refer to a minimum unit for displaying an image, and the plurality of pixel areas are defined to be individually discriminated in each display device.
Each of the plurality of pixel areas includes a thin film transistor so as to be independently driven. As the TFTs operate, a certain voltage is applied to pixel electrodes and light is applied from a light source to display an image.
An area ratio of a region to the entire area of a single pixel area, where light is transmitted, is called an aperture ratio.
An array substrate of the LCD includes a storage capacitor to maintain the voltage that has been applied to a liquid crystal capacitor until the next signal. In this respect, in order to secure the same capacitance of the storage capacitor according to increases in the resolution and driving frequency of the display substrates, the area of the storage capacitor should increase. However, in the related art, increase in the area of the storage capacitor formed of an opaque conductive layer causes a reduction in the aperture ratio.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.